A219974 Number of tilings of a 10 X n rectangle using straight (3 X 1) trominoes and 2 X 2 tiles.

1, 0, 7, 58, 286, 3068, 29876, 214485, 1910822, 17671945, 141365332, 1225043571, 10871708273, 90688536786, 781019641877, 6800784990468, 57716277595775, 496096480109463, 4284929501626939, 36621478929328140, 314572431365390797, 2707867101849205129

Offset

0,3

Links

Table of n, a(n) for n=0..21.

Example

a(2) = 7, because there are 7 tilings of a 10 X 2 rectangle using straight (3 X 1) trominoes and 2 X 2 tiles:
.___.   .___.   .___.   .___.   .___.   .___.   .___.
|   |   |   |   |   |   | | |   |   |   | | |   | | |
|___|   |___|   |___|   | | |   |___|   | | |   | | |
|   |   |   |   | | |   |_|_|   | | |   |_|_|   |_|_|
|___|   |___|   | | |   |   |   | | |   |   |   | | |
|   |   | | |   |_|_|   |___|   |_|_|   |___|   | | |
|___|   | | |   |   |   |   |   | | |   | | |   |_|_|
|   |   |_|_|   |___|   |___|   | | |   | | |   |   |
|___|   | | |   | | |   | | |   |_|_|   |_|_|   |___|
|   |   | | |   | | |   | | |   |   |   |   |   |   |
|___|   |_|_|   |_|_|   |_|_|   |___|   |___|   |___|

Crossrefs

Column k=10 of A219967.

Sequence in context: A290847 A324420 A225160 * A266051 A202975 A051816

Adjacent sequences: A219971 A219972 A219973 * A219975 A219976 A219977

Keyword

nonn

Author

Alois P. Heinz, Dec 02 2012

Status

approved